This invention relates generally to an injection or vulcanization mold device for forming articles, such as footwear, and having male and female dies with a fabric liner covering the male die and with the female die spaced therefrom to define a mold cavity, liner retaining pins on the male die being located near the upper end of the fabric. More particularly, the liner is capable of being automatically stripped from the retaining pins after the molding operation.
When fabricating footwear, particularly boots, from thermoplastic material, a fabric sock is pulled onto the boot last prior to the mold injecting operation. The fabric sock must fit tightly and remain immovable in position on the boot last for the duration of the mold injection operation, as well as prior to such operation. Typically provided are fabric retaining pins rigidly mounted on the male die or boot last with the tips thereof projecting outwardly of the peripheral wall of the boot last and being located above the actual mold cavity at the upper border area of the fabric sock, which is subsequently removed by cutting to obtain a clean upper edge of the boot leg after the injection mold operation. The pins are distributed about the peripheral wall of the boot last so that a fold-free, tight and positively fitting retention of the fabric sock is effected.
When fabricating boots, prior to the mold injection operation and the closing of the female die, the fabric sock is pulled by hand onto the boot last and is lifted over the retaining pins so that the sock is pierced by the pins at its upper border area so as to be thereby maintained securely in place. The hinged female die is then closed and the mold cavity is filled with a plastic material which is intimately bonded with the outer surface of the fabric sock to form a two-layer boot structure. After the hinged female die is opened to facilitate removal of the finished boot, the upper border area of the fabric sock not coated with the plastic material must be stripped from the pins which continue to hold it, or it must be torn away. This procedure is carried out manually and requires a certain amount of expended time which could otherwise be saved during the fabrication process. Moreover, the fabric sock and/or the molded boot may be damaged when pulling the upper area of the fabric sock off the pins. And, if the pins remain engaged with the fabric sock and if the boot, which is still soft, is torn from the boot last, such could easily be damaged or deformed. Besides, during the removal of the fabric sock from the retaining pins, torn pieces of the sock could reach the mold cavity, which is undesirable.